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CVE-2020-4044

HIGHCVSS 7.8/10EPSS 2.40%

Last modified

CVE-2020-4044 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. EPSS estimates a 2.40% chance of exploitation in the next 30 days.

Description

The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
2.40%

82.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
NeutrinolabsXrdp< 0.9.13.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-4044?
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
How severe is CVE-2020-4044?
CVE-2020-4044 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 2.40% probability of exploitation in the next 30 days.
How do I fix CVE-2020-4044?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-4044?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST